As atomics moves ahead, such radiotherapy as Cobalt-60, linear accelerators and electron beams has been one of major means to cancer therapy. However, conventional photon or electron therapy has been undergone physical restrictions of radioactive rays; for example, many normal tissues on a beam path will be damaged as tumor cells are destroyed. On the other hand, sensitivity of tumor cells to the radioactive rays differs greatly, so in most cases, conventional radiotherapy falls short of treatment effectiveness on radioresistant malignant tumors (such as glioblastoma multiforme and melanoma).
For the purpose of reducing radiation damage to the normal tissue surrounding a tumor site, target therapy in chemotherapy has been employed in the radiotherapy. While for high-radioresistant tumor cells, radiation sources with high RBE (relative biological effectiveness) including such as proton, heavy particle and neutron capture therapy have also developed. Among them, the neutron capture therapy combines the target therapy with the RBE, such as the boron neutron capture therapy (BNCT). By virtue of specific grouping of boronated pharmaceuticals in the tumor cells and precise neutron beam regulation, BNCT is provided as a better cancer therapy choice than conventional radiotherapy.
BNCT takes advantage that the boron (10B)-containing pharmaceuticals have high neutron capture cross section and produces 4He and 7Li heavy charged particles through 10(n,α)7Li neutron capture and nuclear fission reaction. The total range of the two particles approximately amounts to a cell size. Therefore, radiation damage to living organisms may be restricted at the cells' level. When the boronated pharmaceuticals are gathered in the tumor cells selectively, only the tumor cells will be destroyed locally with a proper neutron source on the premise of having no major normal tissue damage.
Three-dimensional model is widely used in scientific experiment analysis, scientific experiment simulation field. For example, in the field of nuclear radiation and protection, in order to simulate the dose absorbed by the human body under certain radiation conditions, it is often necessary to process the medical image data by using computer technology to establish an accurate lattice model required by MCNP and combine with MCNP (Monte Carlo Program) for simulation.
At present, the Monte Carlo method is a tool that can accurately simulate the collision trajectory and energy distribution of the nuclear particle in the three-dimensional space of the irradiated target. The combination of the Monte Carlo method with a complex three-dimensional human anatomy model represents a leap forward of simulation in computer technology. In diagnostic radiographic examination, accurate human organ dose assessment is very beneficial for radiation therapy. At present around the world, a variety of human models have been successfully established and combined with Monte Carlo simulation program to evaluate the accuracy of the human body's absorbed dose in the radiation environment. It is a prerequisite for Monte Carlo simulation to successfully transform the three-dimensional anatomical model of human body into geometric description required by Monte Carlo program. It is also the hot and difficult point of Monte Carlo simulation in the world at present.
Medical image data such as Magnetic Resonance Imaging (MRI) or Computed Tomography (CT) can provide detailed tissue geometry information specific for human body features and provide data basis for physical modeling of human internal structures. In the field of neutron capture therapy, it is an important issue how to establish the geometric model required by MCNP based on medical image data. In other words, how to build the lattice model required by the MCNP software input file based on the medical image data so as to improve the accuracy of the treatment plan.
Therefore, it is necessary to propose a method of establishing a geometric model needed for MCNP based on medical image data to improve the accuracy of treatment plan.
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.